1. Field of the Invention
The present invention relates to an endoscope apparatus for capturing an image of living tissue and performing signal processing.
2. Description of the Related Art
An endoscope apparatus, which irradiates an illumination light and obtains an endoscopic image of the inside of a body cavity, has been widely utilized for some time now. This type of endoscope apparatus utilizes an electronic endoscope, which includes image-capturing means for introducing illumination light from a light-source apparatus using a light guide or the like inside a body cavity, and capturing an image of an object by the return light thereof, and by performing signal processing on the image-capturing signal from the image-capturing means using a video processor, displays an endoscopic image on an observation monitor for observation of a diseased part or other such observation site.
When performing ordinary observation of living tissue via an endoscope apparatus, a light-source apparatus emits white light in the visible light region, and, for example, irradiates surface-sequential light on an object via an RGB or other such rotating filter, and can produce a color image either by using a video processor to synchronize and perform image processing of the return light from the surface-sequential light, or by arranging a color chip on the front face of the image-capturing surface of the image-capturing means of the endoscope, capturing an image by separating the return light from the white light into its respective color components via the color chip, and using a video processor to perform image processing.
By contrast, since the absorption characteristics and scattering characteristics of light differ in accordance with the wavelength of irradiated light, for example, in Japanese Patent Laid-open No. 2002-95635, there is proposed a narrowband-light endoscope apparatus, which irradiates narrowband RGB surface-sequential light of discrete spectral characteristics of illumination light in the visible light region onto living tissue, and obtains tissue information of a desired depth of the living tissue.